1. Field of the Invention
The present invention relates to a cooling method for cooling substrates to be processed such as LCD substrates and silicon substrates, a cooling apparatus thereof, and a processing apparatus therewith.
2. Description of the Related Art
When a semiconductor device or a liquid display (LCD) is fabricated, a photo-resist solution is coated on a semiconductor wafer as a substrate or an LCD substrate. Thus, a resist film is formed. Thereafter, the resist film is exposed corresponding to a circuit pattern. The resultant resist film is developed. In other words, a circuit pattern is formed by so-called photo-lithography technology.
In such coating and developing processes, to stably form a resist film, heat processes such as a pre-baking process, a post-exposure baking process, and a post-baking process are performed. In addition, a cooling process for cooling such a heated substrate is performed.
When a heated substrate is cooled, the heat is exchanged on a cooling plate that supports the substrate. In reality, a heated substrate is disposed on a cooling plate with a cold water circulating pipe. Heat is exchanged between the cooling water and the substrate and thereby the temperature of the substrate is lowered.
However, in the conventional substrate cooling method, to shorten the time, the substrate should be effectively cooled. To do that, the substrate should directly contact the entire surface of the cooling plate. In this case, after the substrate is cooled, when it is dismounted from the cooling plate, static electricity occurs. Thus, the substrate is charged.
In addition, in the heat exchange method with the cooling plate, the response characteristic against the temperature adjustment deteriorates and becomes inaccurate.